A key aspect of the S-matrix program is the expectation that scattering amplitudes should be largely determinable from a thorough understanding of their analytic structure. In recent years planar \(\mathcal {N}=4\)  super-Yang-Mills (SYM) theory has served as an exemplar of this approach [1]}. In particular, the assumption that the singularities of all six- and seven-point amplitudes are encoded in symbol letters that are cluster variables [2]}, [3]}, together with physical input from near-collinear and multi-Regge kinematics, has allowed them to be determined to high loop order (see [4]} for a review).
